About one in 5000 individuals is affected with the multisystem tumor disorder Tuberous sclerosis. It is named after the "tuber" like growths that can develop in brain. Other growths can occur in skin, eye, heart, kidney, lung, or bone. Life expectancy is usually normal, although the tumors in the brain can cause mental disabilities or siezures. Tuberous sclerosis is inherited in an autosomal dominant pattern,although most cases are due to new mutations. At least two different genes are thought to be responsible for Tuberous sclerosis. TSC1 is located on the long arm of chromosome 9, near the ABO blood group gene. There is also TSC2 on chromosome 16.
Noonan syndrome (NS) is characterized by short stature, congenital heart defect; broad or webbed neck, unusual chest shape, low-set nipples, developmental delay, and characteristic facies. Congenital heart disease occurs in 50 to 80% of individuals. About one in 1000 individuals is affected. Noonan syndrome is inherited in an autosomal dominant pattern, but most cases are due to new mutations. Recently the PTPN11 gene was identified as being responsible for many cases of Noonan syndrome.
Ehlers–Danlos syndrome (EDS) is a group of heritable disorders involving overly stretchy connective tissue. Common signs include soft velvet–like skin, fragile skin that tears or bruises easily, slow and poor wound healing, joint hypermobility (or "double jointed"), loose/unstable joints which are prone to frequent dislocations. The fragile skin and unstable joints found in EDS are the result of faulty collagen. They usually can do some pretty funky tricks with their body. It is beleived that the best contortionists have EDS. Less commonly, vital tissues can be overstretched, like rupture of arteries near the heart or rupture of the uterus during pregnancy.
Most forms of EDS are inherited in an autosomal dominant manner. Also the type of EDS "runs true" in each family, meaning similar symptoms are seen from parent to child.